Patent GB-1480280-A (GB)
Title: Method of adhering sheets together and adhesive composition therefor
IPC: C09J5/00
Filed: 1974-12-11
Abstract: 1480280 Bookbinding adhesives FUJI PHOTO FILM CO Ltd 11 Dec 1974 [11 Dec 1973 (2) 28 Dec 1973 19 Feb 1974] 53651/74 Heading B6A [Also in Division C3] Sheets of a sheet material such as pressure sensitive copying paper, are adhered together by applying to at least one of the cut edges of a stack of such sheets an adhesive composition comprising (a) 5-40% wt. based on the weight of the composition of a condensation product of formaldehyde with a naphthalene sulphonic acid or a salt thereof, the naphthalene nucleus being optionally alkyl-substituted and (b) at least one of the following compounds:- (i) a water-soluble metal salt (ii) an organic acid, and (iii) a water-soluble polymer selected from an alginic acid salt other than sodium alginate, pectin, gum tragacanth, gluten, methyl cellulose, ethyl cellulose, hydroxy-ethyl starch, cyanoethyl carboxymethyl starch, maleated starch, starch phosphate, an oxidized starch, polyethylene oxide, polyvinyl methyl ether, a copolymer of styrene with methacrylic acid, a copolymer of acrylic acid with vinyl acetate, dimethyl itaconate or acylonitrile, a terpolymer of acrylic acid acrylamide and either styrene or acrylonitrile, or a maleic acid polymer. The sheets of the stack may be selectively separated into multi-ply sets and after use the individual sheets of each set may be separated from one another. Pressure-sensitive copying papers which can be adhered as above are made up in sets composed of (A) a sheet having coated thereon a layer containing a microencapsulated colour former; (B) optionally one or more sheets having on one surface a layer containing a microencapsulated colour former and on the other surface a layer containing a colour developer, and (C) a sheet coated only by a a layer of a colour-developer, the sets being superposed one above the other. In the Examples sheets of pressure-sensitive copying papers as above are adhered using aqueous adhesives comprising a sodium salt of a naphthalene sulphonate - formaldehyde condensate and either (1) sodium sulphate; or (2) zinc chloride; or (3) aluminium sulphate; or (4) sodium sulphate and a carboxy-modified styrene butadiene latex; or (5) sodium sulphate and polyvinyl alcohol; or (6) sodium carboxymethylcellulose and zinc chloride; or (7) styrene-butadiene latex, sodium sulphate and an aqueous solution of either sodium pyrrolidone carboxylate or potassium acetate or sodium p-toluene sulphonate or (8) sodium sulphate, methylmethacrylateethylacrylate copolymer latex, sodium pyrrolidone carboxylate and polyvinyl alcohol. Component (a) preferably has the general formula wherein R is an alkyl group, X is hydrogen, an alkali metal or an ammonium group n is an integer, preferably 1-13, and x is 0-5. Component b(i) may be a salt of a mono-, di- or trivalent metal and an inorganic acid, preferably potassium, sodium or zinc sulphate, or zinc chloride; or an alkali metal salt of an organic acid, e.g. the organic acid of component b(ii). The composition may comprise 0À1-6% wt. of the salt of the inorganic acid based on the weight of the composition, or 1-100% wt. of the salt of the organic acid, based on the weight of component (a). Component b(ii) may be a mono- or polycarboxylic acid, a sulphonic acid or a phenol. Preferred organic acids are aliphatic carboxylic acids such as formic or acetic acid; heterocyclic carboxylic acids such as pyrrolidone-carboxylic acid, and aromatic sulphonic acids such as p-toluenesulphonic acid. Component b(ii) is preferably used in an amount of from 1-100% wt. based on component (a). Component b(iii) is preferably present in an amount of 0À1-20% wt. based on component (a). The adhesive composition may further contain an aqueous emulsion of a water insoluble polymer, e.g. latices of styrene-butadiene rubber, butadiene-acrylonitrile rubber, chloroprene rubber, vinyl acetate polymers, acrylic polymers, vinyl chloride polymers, polybutadiene, polyisoprene or butyl rubber, and is preferably present in an amount of from 10- 300% wt. based on component (a). The adhesives may further contain a surface active agent such as sodium dodecylbenzene sulphonate, trimethyloctadecyl ammonium chloride, sodium oleate, a polyoxyethylene alkylaryl ether, polyethylene glycol dodecylphenyl ether, sodium lignin sulphonate, sorbitan monooleate, and alkyl betaine of an alkyl imidazole.